This paper synthesizes findings from a series of Urban Institute reports produced under the "Risk and Low-Income Working Families" research initiative funded by the John D. and Catherine T. MacArthur and Annie E. Casey Foundations. The paper places this research in the broader context of literature on economic mobility and income volatility. The report is structured around two key questions: (1) How have economic instability and insecurity changed for America's low-income working families changed over time? and (2) What are the factors that contribute to or offer protection from substantial income losses and promote or inhibit recoveries from such losses? (author abstract)